The invention concerns an arrangement for fastening of electrical and/or electronic power components to a circuit board. The invention also concerns a housing to accommodate electrical and/or electronic power components, especially to accommodate the control and power components. The invention is especially useful with a lifting mechanism.
It is generally known from the state of the art that machines driven by electric motor, such as lifting mechanisms, are provided with an electrical box. In the electrical box are arranged electrical and/or electronic control and power components, essentially providing the power supply and the control of the electric motors, such as the lifting and traveling motors of lifting mechanisms. These control and power components also have the task of providing optional additional functions, such as a monitoring of control and/or end switches, an evaluating of sensors, or an actuating of a signaling device, such as a signal horn.
The power components used are typically electromechanical components, such as contactors, for switching the power supply currents of the electric motors, as well as reversing starters, pole changing starters, power protection switches, motor protection switches, fuses for voltage ratings, and transformers. The control components are usually formed from electronic components. The power components are predominantly wired in conventional manner and electrically connected by such wiring to the electronic components of the controls, located in separate small housings.
In a so-called housing-type electrical box, the entire electrical system of the machine is accommodated, in order to protect it against environmental factors in the form of moisture or inclement weather. Furthermore, the electrical box protects people, who might come in contact with the electrical section when attending the device, from an electric shock. The electrical box has a cover and can be opened and closed in order to install the electrical section and also to maintain it later on. The covers are usually screwed together with the electrical box and their only purpose is to close and seal off the electrical box. The electrical box has a sheet metal construction, as is familiar from switch cabinets, or a plastic construction. The electrical installation is accommodated or fastened in the electrical box by means of so-called top hat rails. With this technique, the individual components and terminal strips are snapped onto appropriately shaped, standardized top hat rails and then wired together in conventional manner. In this construction, special requirements have to be observed for the electrical insulation. Maintaining the insulation category and the required clearances and creep paths requires corresponding expense. Plastic constructions have the advantage here of making it easier to observe the required insulation categories.
The connection of the electrical installation to the electrical components of the machine, especially the lifting mechanism, and to the outside power supply and the control lines, is done by cables, which are led in sealed manner into the electrical housing and connected there to screw or terminal contacts by appropriate terminal strips.
The known solutions do not offer the possibility of easily replacing the entire electrical installation. Accordingly, the electrical installation can only be maintained or repaired in a costly manner. Furthermore, the above-described construction of the electrical system is usually very large and consists of many components difficult to install. Therefore, much labor is involved and the work is accordingly wage-intense.
Furthermore, from German Patent Application DE 36 13 863 A1 there is known a fastening device for electrical components, especially a motor choke for noise suppression and/or current dampening in electrical appliances, on a carrier board. The motor choke is configured as a toroidal core choke with two toroidal cores and a corresponding electrical winding. The electrical component has a housing, from which fastening and locking means extend at the side facing the carrier board, especially a circuit board or printed board. These fastening and locking means consist essentially of a detent leg and a fixation leg, each of them extending from the housing of the electronic component in the direction of the carrier board. The detent leg is divided into a web extending from the housing and a detent lug arranged at its free end. The carrier board has openings arranged corresponding to the cross section of the detent lug, into which the detent legs are inserted and locked there by the detent lug grabbing the carrier plate from behind with spring action. The fixation leg situated next to each detent leg has the task of serving as an abutment to the detent lug and thus establishing the distance between the housing and the carrier board, and also penetrating into the opening of the carrier board for the detent lug and thus locking the detent lug. The fastening and locking means are uniformly distributed about the periphery of the housing; for example, there are six fastening and locking means provided in the round housing of the motor choke. Correspondingly, there are six openings provided in the carrier board. After the electrical component has been fixed on the carrier board, its connection line already stripped of insulation is inserted into a designated borehole of the carrier board and soldered together with it.
Moreover, from German Patent DE 717 067 there is known a device for fastening a coil shell, especially for high-frequency coil sets of radio receivers, on a corresponding base plate. For the fastening, the coil shell is inserted into a slit ring, having an eccentric peripheral surface. The base plate has a borehole to receive the ring, being likewise eccentric. Thus, by twisting the ring in the borehole, one can firmly clamp the coil shell in the borehole via the ring.